Walk Forward Schemes Flashcards
Walk-Forward Scheme
A rolling implementation of
* In-sample optimization
* Out-of-sample testing
Protects against the possibility of one round cross-validation that by chance we chose some input parameters that did well in both in and out-of-sample sets.
Steps for WFS
- initialise training and test period
- optimisation
- test strategies
- slide window
- repeat
- aggregate results
Initialise Training and Test Period
Choose an initial training period and a subsequent test period.
Optimisation
Use the data in the training period to get the optimal parameters.
Test Strategies
Test the strategy with the optimal parameters on the test set.
Slide Window
Move the training and test periods forward in time.
Repeat
Go back to optimisation and repeat the process until you’ve moved through all the available data.
Aggregate Results
Collect performance metrics from each test period
to evaluate the overall performance of the strategy.
All similar - average the results/
Widely different - go and cry.